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select.go
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select.go
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// Copyright 2018 Huan Du. All rights reserved.
// Licensed under the MIT license that can be found in the LICENSE file.
package sqlbuilder
import (
"fmt"
"strconv"
"strings"
)
const (
selectMarkerInit injectionMarker = iota
selectMarkerAfterWith
selectMarkerAfterSelect
selectMarkerAfterFrom
selectMarkerAfterJoin
selectMarkerAfterWhere
selectMarkerAfterGroupBy
selectMarkerAfterOrderBy
selectMarkerAfterLimit
selectMarkerAfterFor
)
// JoinOption is the option in JOIN.
type JoinOption string
// Join options.
const (
FullJoin JoinOption = "FULL"
FullOuterJoin JoinOption = "FULL OUTER"
InnerJoin JoinOption = "INNER"
LeftJoin JoinOption = "LEFT"
LeftOuterJoin JoinOption = "LEFT OUTER"
RightJoin JoinOption = "RIGHT"
RightOuterJoin JoinOption = "RIGHT OUTER"
)
// NewSelectBuilder creates a new SELECT builder.
func NewSelectBuilder() *SelectBuilder {
return DefaultFlavor.NewSelectBuilder()
}
func newSelectBuilder() *SelectBuilder {
args := &Args{}
proxy := &whereClauseProxy{}
return &SelectBuilder{
whereClauseProxy: proxy,
whereClauseExpr: args.Add(proxy),
Cond: Cond{
Args: args,
},
limit: -1,
offset: -1,
args: args,
injection: newInjection(),
}
}
// SelectBuilder is a builder to build SELECT.
type SelectBuilder struct {
*WhereClause
Cond
whereClauseProxy *whereClauseProxy
whereClauseExpr string
cteBuilderVar string
cteBuilder *CTEBuilder
distinct bool
tables []string
selectCols []string
joinOptions []JoinOption
joinTables []string
joinExprs [][]string
havingExprs []string
groupByCols []string
orderByCols []string
order string
limit int
offset int
forWhat string
args *Args
injection *injection
marker injectionMarker
}
var _ Builder = new(SelectBuilder)
// Select sets columns in SELECT.
func Select(col ...string) *SelectBuilder {
return DefaultFlavor.NewSelectBuilder().Select(col...)
}
// TableNames returns all table names in this SELECT statement.
func (sb *SelectBuilder) TableNames() []string {
var additionalTableNames []string
if sb.cteBuilder != nil {
additionalTableNames = sb.cteBuilder.tableNamesForFrom()
}
var tableNames []string
if len(sb.tables) > 0 && len(additionalTableNames) > 0 {
tableNames = make([]string, len(sb.tables)+len(additionalTableNames))
copy(tableNames, sb.tables)
copy(tableNames[len(sb.tables):], additionalTableNames)
} else if len(sb.tables) > 0 {
tableNames = sb.tables
} else if len(additionalTableNames) > 0 {
tableNames = additionalTableNames
}
return tableNames
}
// With sets WITH clause (the Common Table Expression) before SELECT.
func (sb *SelectBuilder) With(builder *CTEBuilder) *SelectBuilder {
sb.marker = selectMarkerAfterWith
sb.cteBuilderVar = sb.Var(builder)
sb.cteBuilder = builder
return sb
}
// Select sets columns in SELECT.
func (sb *SelectBuilder) Select(col ...string) *SelectBuilder {
sb.selectCols = col
sb.marker = selectMarkerAfterSelect
return sb
}
// SelectMore adds more columns in SELECT.
func (sb *SelectBuilder) SelectMore(col ...string) *SelectBuilder {
sb.selectCols = append(sb.selectCols, col...)
sb.marker = selectMarkerAfterSelect
return sb
}
// Distinct marks this SELECT as DISTINCT.
func (sb *SelectBuilder) Distinct() *SelectBuilder {
sb.distinct = true
sb.marker = selectMarkerAfterSelect
return sb
}
// From sets table names in SELECT.
func (sb *SelectBuilder) From(table ...string) *SelectBuilder {
sb.tables = table
sb.marker = selectMarkerAfterFrom
return sb
}
// Join sets expressions of JOIN in SELECT.
//
// It builds a JOIN expression like
//
// JOIN table ON onExpr[0] AND onExpr[1] ...
func (sb *SelectBuilder) Join(table string, onExpr ...string) *SelectBuilder {
sb.marker = selectMarkerAfterJoin
return sb.JoinWithOption("", table, onExpr...)
}
// JoinWithOption sets expressions of JOIN with an option.
//
// It builds a JOIN expression like
//
// option JOIN table ON onExpr[0] AND onExpr[1] ...
//
// Here is a list of supported options.
// - FullJoin: FULL JOIN
// - FullOuterJoin: FULL OUTER JOIN
// - InnerJoin: INNER JOIN
// - LeftJoin: LEFT JOIN
// - LeftOuterJoin: LEFT OUTER JOIN
// - RightJoin: RIGHT JOIN
// - RightOuterJoin: RIGHT OUTER JOIN
func (sb *SelectBuilder) JoinWithOption(option JoinOption, table string, onExpr ...string) *SelectBuilder {
sb.joinOptions = append(sb.joinOptions, option)
sb.joinTables = append(sb.joinTables, table)
sb.joinExprs = append(sb.joinExprs, onExpr)
sb.marker = selectMarkerAfterJoin
return sb
}
// Where sets expressions of WHERE in SELECT.
func (sb *SelectBuilder) Where(andExpr ...string) *SelectBuilder {
if len(andExpr) == 0 || estimateStringsBytes(andExpr) == 0 {
return sb
}
if sb.WhereClause == nil {
sb.WhereClause = NewWhereClause()
}
sb.WhereClause.AddWhereExpr(sb.args, andExpr...)
sb.marker = selectMarkerAfterWhere
return sb
}
// AddWhereClause adds all clauses in the whereClause to SELECT.
func (sb *SelectBuilder) AddWhereClause(whereClause *WhereClause) *SelectBuilder {
if sb.WhereClause == nil {
sb.WhereClause = NewWhereClause()
}
sb.WhereClause.AddWhereClause(whereClause)
return sb
}
// Having sets expressions of HAVING in SELECT.
func (sb *SelectBuilder) Having(andExpr ...string) *SelectBuilder {
sb.havingExprs = append(sb.havingExprs, andExpr...)
sb.marker = selectMarkerAfterGroupBy
return sb
}
// GroupBy sets columns of GROUP BY in SELECT.
func (sb *SelectBuilder) GroupBy(col ...string) *SelectBuilder {
sb.groupByCols = append(sb.groupByCols, col...)
sb.marker = selectMarkerAfterGroupBy
return sb
}
// OrderBy sets columns of ORDER BY in SELECT.
func (sb *SelectBuilder) OrderBy(col ...string) *SelectBuilder {
sb.orderByCols = append(sb.orderByCols, col...)
sb.marker = selectMarkerAfterOrderBy
return sb
}
// Asc sets order of ORDER BY to ASC.
func (sb *SelectBuilder) Asc() *SelectBuilder {
sb.order = "ASC"
sb.marker = selectMarkerAfterOrderBy
return sb
}
// Desc sets order of ORDER BY to DESC.
func (sb *SelectBuilder) Desc() *SelectBuilder {
sb.order = "DESC"
sb.marker = selectMarkerAfterOrderBy
return sb
}
// Limit sets the LIMIT in SELECT.
func (sb *SelectBuilder) Limit(limit int) *SelectBuilder {
sb.limit = limit
sb.marker = selectMarkerAfterLimit
return sb
}
// Offset sets the LIMIT offset in SELECT.
func (sb *SelectBuilder) Offset(offset int) *SelectBuilder {
sb.offset = offset
sb.marker = selectMarkerAfterLimit
return sb
}
// ForUpdate adds FOR UPDATE at the end of SELECT statement.
func (sb *SelectBuilder) ForUpdate() *SelectBuilder {
sb.forWhat = "UPDATE"
sb.marker = selectMarkerAfterFor
return sb
}
// ForShare adds FOR SHARE at the end of SELECT statement.
func (sb *SelectBuilder) ForShare() *SelectBuilder {
sb.forWhat = "SHARE"
sb.marker = selectMarkerAfterFor
return sb
}
// As returns an AS expression.
func (sb *SelectBuilder) As(name, alias string) string {
return fmt.Sprintf("%s AS %s", name, alias)
}
// BuilderAs returns an AS expression wrapping a complex SQL.
// According to SQL syntax, SQL built by builder is surrounded by parens.
func (sb *SelectBuilder) BuilderAs(builder Builder, alias string) string {
return fmt.Sprintf("(%s) AS %s", sb.Var(builder), alias)
}
// LateralAs returns a LATERAL derived table expression wrapping a complex SQL.
func (sb *SelectBuilder) LateralAs(builder Builder, alias string) string {
return fmt.Sprintf("LATERAL (%s) AS %s", sb.Var(builder), alias)
}
// NumCol returns the number of columns to select.
func (sb *SelectBuilder) NumCol() int {
return len(sb.selectCols)
}
// String returns the compiled SELECT string.
func (sb *SelectBuilder) String() string {
s, _ := sb.Build()
return s
}
// Build returns compiled SELECT string and args.
// They can be used in `DB#Query` of package `database/sql` directly.
func (sb *SelectBuilder) Build() (sql string, args []interface{}) {
return sb.BuildWithFlavor(sb.args.Flavor)
}
// BuildWithFlavor returns compiled SELECT string and args with flavor and initial args.
// They can be used in `DB#Query` of package `database/sql` directly.
func (sb *SelectBuilder) BuildWithFlavor(flavor Flavor, initialArg ...interface{}) (sql string, args []interface{}) {
buf := newStringBuilder()
sb.injection.WriteTo(buf, selectMarkerInit)
oraclePage := flavor == Oracle && (sb.limit >= 0 || sb.offset >= 0)
if sb.cteBuilderVar != "" {
buf.WriteLeadingString(sb.cteBuilderVar)
sb.injection.WriteTo(buf, selectMarkerAfterWith)
}
if len(sb.selectCols) > 0 {
buf.WriteLeadingString("SELECT ")
if sb.distinct {
buf.WriteString("DISTINCT ")
}
if oraclePage {
var selectCols = make([]string, 0, len(sb.selectCols))
for i := range sb.selectCols {
cols := strings.SplitN(sb.selectCols[i], ".", 2)
if len(cols) == 1 {
selectCols = append(selectCols, cols[0])
} else {
selectCols = append(selectCols, cols[1])
}
}
buf.WriteStrings(selectCols, ", ")
} else {
buf.WriteStrings(sb.selectCols, ", ")
}
}
sb.injection.WriteTo(buf, selectMarkerAfterSelect)
if oraclePage {
if len(sb.selectCols) > 0 {
buf.WriteLeadingString("FROM ( SELECT ")
if sb.distinct {
buf.WriteString("DISTINCT ")
}
var selectCols = make([]string, 0, len(sb.selectCols)+1)
selectCols = append(selectCols, "ROWNUM r")
for i := range sb.selectCols {
cols := strings.SplitN(sb.selectCols[i], ".", 2)
if len(cols) == 1 {
selectCols = append(selectCols, cols[0])
} else {
selectCols = append(selectCols, cols[1])
}
}
buf.WriteStrings(selectCols, ", ")
buf.WriteLeadingString("FROM ( SELECT ")
buf.WriteStrings(sb.selectCols, ", ")
}
}
tableNames := sb.TableNames()
if len(tableNames) > 0 {
buf.WriteLeadingString("FROM ")
buf.WriteStrings(tableNames, ", ")
}
sb.injection.WriteTo(buf, selectMarkerAfterFrom)
for i := range sb.joinTables {
if option := sb.joinOptions[i]; option != "" {
buf.WriteLeadingString(string(option))
}
buf.WriteLeadingString("JOIN ")
buf.WriteString(sb.joinTables[i])
if exprs := sb.joinExprs[i]; len(exprs) > 0 {
buf.WriteString(" ON ")
buf.WriteStrings(sb.joinExprs[i], " AND ")
}
}
if len(sb.joinTables) > 0 {
sb.injection.WriteTo(buf, selectMarkerAfterJoin)
}
if sb.WhereClause != nil {
sb.whereClauseProxy.WhereClause = sb.WhereClause
defer func() {
sb.whereClauseProxy.WhereClause = nil
}()
buf.WriteLeadingString(sb.whereClauseExpr)
sb.injection.WriteTo(buf, selectMarkerAfterWhere)
}
if len(sb.groupByCols) > 0 {
buf.WriteLeadingString("GROUP BY ")
buf.WriteStrings(sb.groupByCols, ", ")
if len(sb.havingExprs) > 0 {
buf.WriteString(" HAVING ")
buf.WriteStrings(sb.havingExprs, " AND ")
}
sb.injection.WriteTo(buf, selectMarkerAfterGroupBy)
}
if len(sb.orderByCols) > 0 {
buf.WriteLeadingString("ORDER BY ")
buf.WriteStrings(sb.orderByCols, ", ")
if sb.order != "" {
buf.WriteRune(' ')
buf.WriteString(sb.order)
}
sb.injection.WriteTo(buf, selectMarkerAfterOrderBy)
}
switch flavor {
case MySQL, SQLite, ClickHouse:
if sb.limit >= 0 {
buf.WriteLeadingString("LIMIT ")
buf.WriteString(strconv.Itoa(sb.limit))
if sb.offset >= 0 {
buf.WriteLeadingString("OFFSET ")
buf.WriteString(strconv.Itoa(sb.offset))
}
}
case CQL:
if sb.limit >= 0 {
buf.WriteLeadingString("LIMIT ")
buf.WriteString(strconv.Itoa(sb.limit))
}
case PostgreSQL, Presto:
if sb.limit >= 0 {
buf.WriteLeadingString("LIMIT ")
buf.WriteString(strconv.Itoa(sb.limit))
}
if sb.offset >= 0 {
buf.WriteLeadingString("OFFSET ")
buf.WriteString(strconv.Itoa(sb.offset))
}
case SQLServer:
// If ORDER BY is not set, sort column #1 by default.
// It's required to make OFFSET...FETCH work.
if len(sb.orderByCols) == 0 && (sb.limit >= 0 || sb.offset >= 0) {
buf.WriteLeadingString("ORDER BY 1")
}
if sb.offset >= 0 {
buf.WriteLeadingString("OFFSET ")
buf.WriteString(strconv.Itoa(sb.offset))
buf.WriteString(" ROWS")
}
if sb.limit >= 0 {
if sb.offset < 0 {
buf.WriteLeadingString("OFFSET 0 ROWS")
}
buf.WriteLeadingString("FETCH NEXT ")
buf.WriteString(strconv.Itoa(sb.limit))
buf.WriteString(" ROWS ONLY")
}
case Oracle:
if oraclePage {
buf.WriteString(" ) ")
if len(sb.tables) > 0 {
buf.WriteStrings(sb.tables, ", ")
}
min := sb.offset
if min < 0 {
min = 0
}
buf.WriteString(" ) WHERE ")
if sb.limit >= 0 {
buf.WriteString("r BETWEEN ")
buf.WriteString(strconv.Itoa(min + 1))
buf.WriteString(" AND ")
buf.WriteString(strconv.Itoa(sb.limit + min))
} else {
buf.WriteString("r >= ")
buf.WriteString(strconv.Itoa(min + 1))
}
}
case Informix:
// [SKIP N] FIRST M
// M must be greater than 0
if sb.limit > 0 {
if sb.offset >= 0 {
buf.WriteLeadingString("SKIP ")
buf.WriteString(strconv.Itoa(sb.offset))
}
buf.WriteLeadingString("FIRST ")
buf.WriteString(strconv.Itoa(sb.limit))
}
}
if sb.limit >= 0 {
sb.injection.WriteTo(buf, selectMarkerAfterLimit)
}
if sb.forWhat != "" {
buf.WriteLeadingString("FOR ")
buf.WriteString(sb.forWhat)
sb.injection.WriteTo(buf, selectMarkerAfterFor)
}
return sb.args.CompileWithFlavor(buf.String(), flavor, initialArg...)
}
// SetFlavor sets the flavor of compiled sql.
func (sb *SelectBuilder) SetFlavor(flavor Flavor) (old Flavor) {
old = sb.args.Flavor
sb.args.Flavor = flavor
return
}
// Flavor returns flavor of builder
func (sb *SelectBuilder) Flavor() Flavor {
return sb.args.Flavor
}
// SQL adds an arbitrary sql to current position.
func (sb *SelectBuilder) SQL(sql string) *SelectBuilder {
sb.injection.SQL(sb.marker, sql)
return sb
}